Three holdout jurors in the case of an off-duty cop’s gunpoint sex attack were fixated on minor memory lapses of the victim — lapses that were inconsequential to the attack itself, a source familiar with the jury’s postverdict statements said yesterday.

The faction — led by Lloyd Constantine, a one-time legal adviser to ex-Gov. Eliot Spitzer — even held it against the schoolteacher victim that she couldn’t remember the color of a car parked near the Inwood back yard where now-fired cop Michael Pena violated her last August, the source said.

Their indecision ultimately led to this week’s partial verdict, in which Pena was convicted of the top charges of predatory sexual assault carrying a possible life sentence, but was let off the hook on four rape-related charges.

Meanwhile, the judge in the case has sealed the juror-related records concerning the deadlock, barring access to normally available documents that would shed light on the trial outcome.

The victim remains shattered by the verdict, which ran counter to DNA evidence and testimony.

“Everyone involved in bringing sex criminals to justice is disgusted by that verdict,” said one seasoned sex-crimes cop.